Method, system, and apparatus for transfer of dies using a die plate

ABSTRACT

A method, system, and apparatus for transfer of dies using a die plate is described herein. The die plate has a planar body. The body has a plurality of holes therethrough. A support structure and the die plate can be positioned to be closely adjacent to each other such that each die of a plurality of dies attached to the support structure adheres to a first surface of the die plate. The dies can subsequently be transferred from the die plate to one or more destination substrates or other surfaces, by a punching mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/477,735, filed Jun. 12, 2003 (Atty. Dkt. No.1689.0350000), which is herein incorporated by reference in itsentirety.

[0002] The following applications of common assignee are related to thepresent application, have the same filing date as the presentapplication, and are herein incorporated by reference in theirentireties:

[0003] “Method And Apparatus For Expanding A Semiconductor Wafer,” U.S.Ser. No. ______ (Atty. Dkt. No. 1689.0520000);

[0004] “Method, System, And Apparatus For Authenticating Devices DuringAssembly,” U.S. Ser. No. ______ (Atty. Dkt. No. 1689.0530000);

[0005] “Method, System, And Apparatus For Transfer Of Dies Using A DiePlate Having Die Cavities,” U.S. Ser. No. ______ (Atty. Dkt. No.1689.0540000);

[0006] “Method, System, And Apparatus For Transfer Of Dies Using A PinPlate,” U.S. Ser. No. ______ (Atty. Dkt. No. 1689.0560000);

[0007] “Method, System, And Apparatus For High Volume Transfer Of Dies,”U.S. Ser. No. ______ (Atty. Dkt. No. 1689.0580000); and

[0008] “Method, System, And Apparatus For High Volume Assembly OfCompact Discs And Digital Video Discs Incorporating Radio FrequencyIdentification Tag Technology,” U.S. Ser. No. ______ (Atty. Dkt. No.1689.0590000).

[0009] The following applications of common assignee are related to thepresent application, and are herein incorporated by reference in theirentireties:

[0010] “Method and Apparatus for High Volume Assembly of Radio FrequencyIdentification Tags,” U.S. Provisional App. No. 60/400,101, filed Aug.2, 2002 (Atty. Dkt. No. 1689.0110000);

[0011] “Method and Apparatus for High Volume Assembly of Radio FrequencyIdentification Tags,” Ser. No. 10/322,467, filed Dec. 19, 2002 (Atty.Dkt. No. 1689.0110001);

[0012] “Multi-Barrel Die Transfer Apparatus and Method for TransferringDies Therewith,” Ser. No. 10/322,718, filed Dec. 19, 2002 (Atty. Dkt.No. 1689.0110002);

[0013] “Die Frame Apparatus and Method of Transferring Dies Therewith,”Ser. No. 10/322,701, filed Dec. 19, 2002 (Atty. Dkt. No. 1689.0110003);

[0014] “System and Method of Transferring Dies Using an AdhesiveSurface,” Ser. No. 10/322,702, filed Dec. 19, 2002 (Atty. Dkt. No.1689.0110004); and

[0015] “Method and System for Forming a Die Frame and for TransferringDies Therewith,” Ser. No. 10/429,803, filed May 6, 2003 (Atty. Dkt. No.1689.0110005).

BACKGROUND OF THE INVENTION

[0016] 1. Field of the Invention

[0017] The present invention relates generally to the assembly ofelectronic devices. More particularly, the present invention relates tothe transfer of dies from wafers to substrates, including substrates ofradio frequency identification (RFID) tags.

[0018] 2. Related Art

[0019] Pick and place techniques are often used to assemble electronicdevices. Such techniques involve a manipulator, such as a robot arm, toremove integrated circuit (IC) dies from a wafer and place them into adie carrier. The dies are subsequently mounted onto a substrate withother electronic components, such as antennas, capacitors, resistors,and inductors to form an electronic device.

[0020] Pick and place techniques involve complex robotic components andcontrol systems that handle only one die at a time. This has a drawbackof limiting throughput volume. Furthermore, pick and place techniqueshave limited placement accuracy, and have a minimum die sizerequirement.

[0021] One type of electronic device that may be assembled using pickand place techniques is an RFID “tag.” An RFID tag may be affixed to anitem whose presence is to be detected and/or monitored. The presence ofan RFID tag, and therefore the presence of the item to which the tag isaffixed, may be checked and monitored by devices known as “readers.”

[0022] As market demand increases for products such as RFID tags, and asdie sizes shrink, high assembly throughput rates for very small die, andlow production costs are crucial in providing commercially-viableproducts. Accordingly, what is needed is a method and apparatus for highvolume assembly of electronic devices, such as RFID tags, that overcomesthese limitations.

SUMMARY OF THE INVENTION

[0023] The present invention is directed to methods, systems, andapparatuses for producing one or more electronic devices, such as RFIDtags, that each include a die having one or more electrically conductivecontact pads that provide electrical connections to related electronicson a substrate.

[0024] According to the present invention, electronic devices are formedat much greater rates than conventionally possible. In one aspect, largequantities of dies can be transferred directly from a wafer tocorresponding substrates of a web of substrates. In another aspect,large quantities of dies can be transferred from a support surface tocorresponding substrates of a web of substrates. In another aspect,large quantities of dies can be transferred from a wafer or supportsurface to an intermediate surface, such as a die plate. The die platemay have cells formed in a surface thereof in which the dies reside.Otherwise, the dies can reside on a surface of the die plate. The diesof the die plate can then be transferred to corresponding substrates ofa web of substrates.

[0025] In an aspect of the present invention, methods, systems, andapparatuses for transfer of dies using the die plate are describedherein. The die plate has a planar body. The body has a plurality ofholes therethrough.

[0026] In a further aspect, a support structure and the die plate can bepositioned to be closely adjacent to each other such that each die of aplurality of dies attached to the support structure adheres to a firstsurface of the die plate. The dies can subsequently be transferred fromthe die plate to one or more destination substrates or other surfaces,by a punching or other mechanism.

[0027] In an aspect, a punch plate, punch roller or cylinder, orexpandable material can be used to transfer dies from the die plate tosubstrates.

[0028] Large quantities of dies can be transferred. For example, 10s,100s, 1000s, or more dies, or even all dies of a wafer, support surface,or die plate, can be simultaneously transferred to correspondingsubstrates of a web.

[0029] In one aspect, dies may be transferred between surfaces in a“pads up” orientation. When dies are transferred to a substrate in a“pads up” orientation, related electronics can be printed or otherwiseformed to couple contact pads of the die to related electronics of thetag substrate.

[0030] In an alternative aspect, the dies may be transferred betweensurfaces in a “pads down” orientation. When dies are transferred to asubstrate in a “pads down” orientation, related electronics can bepre-printed or otherwise pre-deposited on the tag substrates.

[0031] These and other advantages and features will become readilyapparent in view of the following detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

[0032] The accompanying drawings, which are incorporated herein and forma part of the specification, illustrate the present invention and,together with the description, further serve to explain the principlesof the invention and to enable a person skilled in the pertinent art tomake and use the invention.

[0033]FIG. 1A shows a block diagram of an exemplary RFID tag, accordingto an embodiment of the present invention.

[0034]FIGS. 1B and 1C show detailed views of exemplary RFID tags,according to embodiments of the present invention.

[0035]FIGS. 2A and 2B show plan and side views of an exemplary die,respectively.

[0036]FIGS. 2C and 2D show portions of a substrate with a die attachedthereto, according to example embodiments of the present invention.

[0037]FIG. 3 is a flowchart illustrating a tag assembly process,according to embodiments of the present invention.

[0038]FIGS. 4A and 4B are plan and side views of a wafer having multipledies affixed to a support surface, respectively.

[0039]FIG. 5 is a view of a wafer having separated dies affixed to asupport surface.

[0040]FIG. 6 shows a system diagram illustrating example options fortransfer of dies from wafers to substrates, according to embodiments ofthe present invention.

[0041]FIGS. 7 and 8 show flowcharts providing steps for transferringdies from a first surface to a second surface, according to embodimentsof the present invention.

[0042]FIG. 9 shows a perspective view of an example die plate, accordingto an example embodiment of the present invention.

[0043]FIGS. 10A-10E show multiple schematic views of an example dieplate, according to an embodiment of the present invention.

[0044]FIG. 11 shows a perspective view of a portion of a surface of adie plate, according to an embodiment of the present invention.

[0045]FIG. 12 shows a flowchart providing example steps for transferringdies from a support structure to a die plate, according to embodimentsof the present invention.

[0046]FIGS. 13-15 show example implementations of the steps of theflowchart of FIG. 12, according to embodiments of the present invention.

[0047]FIG. 16 shows a flowchart providing example steps for transferringdies from a wafer to a die plate, according to embodiments of thepresent invention.

[0048]FIGS. 17-19 show example implementations of the steps of theflowchart of FIG. 16, according to embodiments of the present invention.

[0049]FIGS. 20-26 show various views of a transfer of dies to a dieplate, and subsequently to one or more substrates, according toembodiments of the present invention.

[0050]FIG. 27 shows a flowchart providing steps for transferring dies,according to embodiments of the present invention.

[0051] The present invention will now be described with reference to theaccompanying drawings. In the drawings, like reference numbers generallyindicate identical, functionally similar, and/or structurally similarelements. The drawing in which an element first appears is indicated bythe leftmost digit(s) in the reference number.

DETAILED DESCRIPTION OF THE INVENTION

[0052] The present invention provides improved processes and systems forassembling electronic devices, including RFID tags. The presentinvention provides improvements over current processes. Conventionaltechniques include vision-based systems that pick and place dies one ata time onto substrates. The present invention can transfer multiple diessimultaneously. Vision-based systems are limited as far as the size ofdies that may be handled, such as being limited to dies larger than 600microns square. The present invention is applicable to dies 100 micronssquare and even smaller. Furthermore, yield is poor in conventionalsystems, where two or more dies may be accidentally picked up at a time,causing losses of additional dies. The present invention allows forimproved yield values.

[0053] The present invention provides an advantage of simplicity.Conventional die transfer tape mechanisms may be used by the presentinvention. Furthermore, much higher fabrication rates are possible.Current techniques process 5-8 thousand units per hour. The presentinvention can provide improvements in these rates by a factor of N. Forexample, embodiments of the present invention can process dies 5 timesas fast as conventional techniques, at 100 times as fast as conventionaltechniques, and at even faster rates. Furthermore, because the presentinvention allows for flip-chip die attachment techniques, wire bonds arenot necessary.

[0054] Elements of the embodiments described herein may be combined inany manner. Example RFID tags are described in the section below.Assembly embodiments for RFID tags are described in the next section.Example applications for tags and tag assembly techniques are thendescribed, followed by a description of example substrate webs andantenna layouts.

[0055] 1.0 RFID Tag

[0056] The present invention is directed to techniques for producingelectronic devices, such as RFID tags. For illustrative purposes, thedescription herein primarily relates to the production of RFID tags.However, the description is also adaptable to the production of furtherelectronic device types, as would be understood by persons skilled inthe relevant art(s) from the teachings herein.

[0057]FIG. 1A shows a block diagram of an exemplary RFID tag 100,according to an embodiment of the present invention. As shown in FIG.1A, RFID tag 100 includes a die 104 and related electronics 106 locatedon a tag substrate 116. Related electronics 106 includes an antenna 114in the present example. FIGS. 1B and 1C show detailed views of exemplaryRFID tags 100, indicated as RFID tags 100 a and 10 b. As shown in FIGS.1B and 1C, die 104 can be mounted onto antenna 114 of relatedelectronics 106. As is further described elsewhere herein, die 104 maybe mounted in either a pads up or pads down orientation.

[0058] RFID tag 100 may be located in an area having a large number,population, or pool of RFID tags present. RFID tag 100 receivesinterrogation signals transmitted by one or more tag readers. Accordingto interrogation protocols, RFID tag 100 responds to these signals. Eachresponse includes information that identifies the corresponding RFID tag100 of the potential pool of RFID tags present. Upon reception of aresponse, the tag reader determines the identity of the responding tag,thereby ascertaining the existence of the tag within a coverage areadefined by the tag reader.

[0059] RFID tag 100 may be used in various applications, such asinventory control, airport baggage monitoring, as well as security andsurveillance applications. Thus, RFID tag 100 can be affixed to itemssuch as airline baggage, retail inventory, warehouse inventory,automobiles, compact discs (CDs), digital video discs (DVDs), videotapes, and other objects. RFID tag 100 enables location monitoring andreal time tracking of such items.

[0060] In the present embodiment, die 104 is an integrated circuit thatperforms RFID operations, such as communicating with one or more tagreaders (not shown) according to various interrogation protocols.Exemplary interrogation protocols are described in U.S. Pat. No.6,002,344 issued Dec. 14, 1999 to Bandy et al. entitled System andMethod for Electronic Inventory, and U.S. patent application Ser. No.10/072,885, filed on Feb. 12, 2002, both of which are incorporated byreference herein in its entirety. Die 104 includes a plurality ofcontact pads that each provide an electrical connection with relatedelectronics 106.

[0061] Related electronics 106 are connected to die 104 through aplurality of contact pads of IC die 104. In embodiments, relatedelectronics 106 provide one or more capabilities, including RF receptionand transmission capabilities, sensor functionality, power reception andstorage functionality, as well as additional capabilities. Thecomponents of related electronics 106 can be printed onto a tagsubstrate 116 with materials, such as conductive inks. Examples ofconductive inks include silver conductors 5000, 5021, and 5025, producedby DuPont Electronic Materials of Research Triangle Park, N.C. Othermaterials or means suitable for printing related electronics 106 ontotag substrate 116 include polymeric dielectric composition 5018 andcarbon-based PTC resistor paste 7282, which are also produced by DuPontElectronic Materials of Research Triangle Park, N.C. Other materials ormeans that may be used to deposit the component material onto thesubstrate would be apparent to persons skilled in the relevant art(s)from the teachings herein.

[0062] As shown in FIGS. 1A-1C, tag substrate 116 has a first surfacethat accommodates die 104, related electronics 106, as well as furthercomponents of tag 100. Tag substrate 116 also has a second surface thatis opposite the first surface. An adhesive material or backing can beincluded on the second surface. When present, the adhesive backingenables tag 100 to be attached to objects, such as books and consumerproducts. Tag substrate 116 is made from a material, such as polyester,paper, plastic, fabrics such as cloth, and/or other materials such ascommercially available Tyvec®.

[0063] In some implementations of tags 100, tag substrate 116 caninclude an indentation, “cavity,” or “cell” (not shown in FIGS. 1A-1C)that accommodates die 104. An example of such an implementation isincluded in a “pads up” orientation of die 104.

[0064]FIGS. 2A and 2B show plan and side views of an example die 104.Die 104 includes four contact pads 204 a-d that provide electricalconnections between related electronics 106 and internal circuitry ofdie 104. Note that although four contact pads 204 a-d are shown, anynumber of contact pads may be used, depending on a particularapplication. Contact pads 204 are made of an electrically conductivematerial during fabrication of the die. Contact pads 204 can be furtherbuilt up if required by the assembly process, by the deposition ofadditional and/or other materials, such as gold and solder flux. Suchpost processing, or “bumping,” will be known to persons skilled in therelevant art(s).

[0065]FIG. 2C shows a portion of a substrate 116 with die 104 attachedthereto, according to an example embodiment of the present invention. Asshown in FIG. 2C, contact pads 204 a-d of die 104 are coupled torespective contact areas 210 a-d of substrate 116. Contact areas 210 a-dprovide electrical connections to related electronics 106. Thearrangement of contact pads 204 a-d in a rectangular (e.g., square)shape allows for flexibility in attachment of die 104 to substrate 116,and good mechanical adherement. This arrangement allows for a range oftolerance for imperfect placement of IC die 104 on substrate 116, whilestill achieving acceptable electrical coupling between contact pads 204a-d and contact areas 210 a-d. For example, FIG. 2D shows an imperfectplacement of IC die 104 on substrate 116. However, even though IC die104 has been improperly placed, acceptable electrical coupling isachieved between contact pads 204 a-d and contact areas 210 a-d.

[0066] Note that although FIGS. 2A-2D show the layout of four contactpads 204 a-d collectively forming a rectangular shape, greater or lessernumbers of contact pads 204 may be used. Furthermore, contact pads 204a-d may be laid out in other shapes in embodiments of the presentinvention.

[0067] 2.0 RFID Tag Assembly

[0068] The present invention is directed to continuous-roll assemblytechniques and other techniques for assembling tags, such as RFID tag100. Such techniques involve a continuous web (or roll) of the materialof the tag antenna substrate 116 that is capable of being separated intoa plurality of tags. Alternatively, separate sheets of the material canbe used as discrete substrate webs that can be separated into aplurality of tags. As described herein, the manufactured one or moretags can then be post processed for individual use. For illustrativepurposes, the techniques described herein are made with reference toassembly of RFID tag 100. However, these techniques can be applied toother tag implementations and other suitable devices, as would beapparent to persons skilled in the relevant art(s) from the teachingsherein.

[0069] The present invention advantageously eliminates the restrictionof assembling electronic devices, such as RFID tags, one at a time,allowing multiple electronic devices to be assembled in parallel. Thepresent invention provides a continuous-roll technique that is scalableand provides much higher throughput assembly rates than conventionalpick and place techniques.

[0070]FIG. 3 shows a flowchart 300 with example steps relating tocontinuous-roll production of RFID tags 100, according to exampleembodiments of the present invention. FIG. 3 shows a flowchartillustrating a process 300 for assembling tags 100. Process 300 beginswith a step 302. In step 300, a wafer 400 having a plurality of dies 104is produced. FIG. 4A illustrates a plan view of an exemplary wafer 400.As illustrated in FIG. 4A, a plurality of dies 104 are arranged in aplurality of rows 402 a-n.

[0071] In a step 304, wafer 400 is optionally applied to a supportstructure or surface 404. Support surface 404 includes an adhesivematerial to provide adhesiveness. For example support surface 404 may bean adhesive tape that holds wafer 400 in place for subsequentprocessing. FIG. 4B shows an example view of wafer 400 in contact withan example support surface 404. In some embodiments, wafer 400 does notneed to be attached to a support surface, and can be operated ondirectly.

[0072] In a step 306, the plurality of dies 104 on wafer 400 areseparated. For example, step 306 may include scribing wafer 400according to a process, such as laser etching. FIG. 5 shows a view ofwafer 400 having example separated dies 104 that are in contact withsupport surface 404. FIG. 5 shows a plurality of scribe lines 502 a-1that indicate locations where dies 104 are separated.

[0073] In a step 308, the plurality of dies 104 is transferred to asubstrate. For example, dies 104 can be transferred from support surface404 to tag substrates 116. Alternatively, dies 104 can be directlytransferred from wafer 400 to substrates 116. In an embodiment, step 308may allow for “pads down” transfer. Alternatively, step 308 may allowfor “pads up” transfer. As used herein the terms “pads up” and “padsdown” denote alternative implementations of tags 100. In particular,these terms designate the orientation of connection pads 204 in relationto tag substrate 116. In a “pads up” orientation for tag 100, die 104 istransferred to tag substrate 116 with pads 204 a-204 d facing away fromtag substrate 116. In a “pads down” orientation for tag 100, die 104 istransferred to tag substrate 116 with pads 204 a-204 d facing towards,and in contact with tag substrate 116.

[0074] Note that step 308 may include multiple die transfer iterations.For example, in step 308, dies 104 may be directly transferred from awafer 400 to substrates 116. Alternatively, dies 104 may be transferredto an intermediate structure, and subsequently transferred to substrates116. Example embodiments of such die transfer options are describedbelow.

[0075] Note that steps 306 and 308 can be performed simultaneously insome embodiments. This is indicated in FIG. 3 by step 320, whichincludes both of steps 306 and 308. Example embodiments where dies 104of a wafer 400 are separated, and simultaneously transferred to asubsequent surface, are described below.

[0076] In a step 310, post processing is performed. During step 310,assembly of RFID tag(s) 100 is completed.

[0077] 2.1 Die Transfer Embodiments

[0078] Step 308 shown in FIG. 3, and discussed above, relates totransferring dies to a tag substrate. The dies can be attached to asupport surface (e.g., as shown in FIG. 5), or can be transferreddirectly from the wafer, and can be transferred to the tag substrate bya variety of techniques. Conventionally, the transfer is accomplishedusing a pick and place tool. The pick and place tool uses a vacuum diecollet controlled by a robotic mechanism that picks up the die from thesupport structure by a suction action, and holds the die securely in thedie collet. The pick and place tool deposits the die into a die carrieror transfer surface. For example, a suitable transfer surface is a“punch tape” manufactured by Mulbauer, Germany. A disadvantage of thepresent pick and place approach is that only one die at a time may betransferred. Hence, the present pick and place approach does not scalewell for very high throughput rates.

[0079] The present invention allows for the transfer of more than onedie at a time from a support surface to a transfer surface. In fact, thepresent invention allows for the transfer of more than one die betweenany two surfaces, including transferring dies from a wafer or supportsurface to an intermediate surface, transferring dies between multipleintermediate surfaces, transferring dies between an intermediate surfaceand the final substrate surface, and transferring dies directly from awafer or support surface to the final substrate surface.

[0080]FIG. 6 shows a high-level system diagram 600 that provides arepresentation of the different modes or paths of transfer of dies fromwafers to substrates. FIG. 6 shows a wafer 400, a web 608, and atransfer surface 610. Two paths are shown in FIG. 6 for transferringdies, a first path 602, which is a direct path, and a second path 604,which is a path having intermediate steps. For example, as shown in FIG.6, first path 602 leads directly from wafer 400 to web 608. In otherwords, dies can be transferred from wafer 400 to substrates of web 608directly, without the dies having first to be transferred from wafer 400to another surface or storage structure. However, according to path 604,at least two steps are required, path 604A and path 604B. For path 604A,dies are first transferred from wafer 400 to an intermediate transfersurface 610. The dies then are transferred from transfer surface 610 viapath 604B to the substrates of web 608. Paths 602 and 604 each havetheir advantages. For example, path 602 can have fewer steps, but canhave issues of die registration, and other difficulties. Path 604typically has a larger number of steps than path 602, but transfer ofdies from wafer 400 to a transfer surface 610 can make die transfer tothe substrates of web 608 easier, as die registration may be easier.

[0081]FIGS. 7 and 8 show flowcharts providing steps for transferringdies from a first surface to a second surface, according to embodimentsof the present invention. Structural embodiments of the presentinvention will be apparent to persons skilled in the relevant art(s)based on the following discussion. These steps are described in detailbelow.

[0082] Flowchart 700 begins with step 702. In step 702, a plurality ofdies attached to a support surface is received. For example, the diesare dies 104, which are shown attached to a support surface 404 in FIG.4A. For example, the support surface can be a “green tape” or “bluetape” as would be known to persons skilled in the relevant art(s).

[0083] In step 704, the plurality of dies are transferred to asubsequent surface. For example, dies 104 may be transferred accordingto embodiments of the present invention. For example, the dies may betransferred by an adhesive tape, a punch tape, a multi-barrel transportmechanism and/or process, die frame, pin plate, such as are furtherdescribed below and/or in the incorporated patent applications, and maybe transferred by other mechanisms and processes, or by combinations ofthe mechanisms/processes described herein. In embodiments, thesubsequent surface can be an intermediate surface or an actual finalsubstrate. For example, the intermediate surface can be a transfersurface, including a “blue tape,” as would be known to persons skilledin the relevant art(s). When the subsequent surface is a substrate, thesubsequent surface may be a substrate structure that includes aplurality of tag substrates, or may be another substrate type.

[0084] In block 706, if the subsequent surface is a substrate to whichthe dies are going to be permanently attached, the process of flowchart700 is complete. The process can then proceed to step 310 of flowchart300, if desired. If the subsequent surface is not a final surface, thenthe process proceeds to step 704, where the plurality of dies are thentransferred to another subsequent surface. Step 704 may be repeated asmany times as is required by the particular application.

[0085] Flowchart 800 of FIG. 8 is substantially similar to flowchart of700. However, instead of including step 702, flowchart 800 includes step802. In step 802, a wafer that includes a plurality of dies is received.Thus, in flowchart 800, a wafer 400 is operated on directly, withoutbeing applied to a support surface or structure. Embodiments for both offlowcharts 700 and 800 are described herein.

[0086] Any of the intermediate/transfer surfaces and final substratesurfaces may or may not have cells formed therein for dies to residetherein. Various processes described below may be used to transfermultiple dies simultaneously between first and second surfaces,according to embodiments of the present invention. In any of theprocesses described herein, dies may be transferred in either pads-up orpads-down orientations from one surface to another.

[0087] The die transfer processes described herein include transferusing an adhesive surface, a parallel die punch process, die plates,including die receptacle structures, pin plates, die transfer heads, anddie transfer head coverage patterns. Elements of the die transferprocesses described herein may be combined in any way, as would beunderstood by persons skilled in the relevant art(s). These die transferprocesses, and related example structures for performing theseprocesses, are further described in the following subsections.

[0088] 2.1.1 Die Transfer onto a Die Plate

[0089] According to an embodiment of the present invention, a die plateis used for transferring dies from wafers or support surfaces tosubstrates or subsequent transfer services. According to die plateembodiments described herein, dies 104 can be attached to a surface ofthe die plate, being positioned over a corresponding hole of the dieplate. Once a die is transferred to the die plate, the die can then betransferred to subsequent, intermediate/transfer surfaces, or to a finalsurface or structure, such as a substrate.

[0090]FIG. 9 shows an example die plate 900, according to an exampleembodiment of the present invention. As shown in FIG. 9, die plate 900includes a body 902. As shown in FIG. 9, body 902 is substantiallyplanar. Body 902 can be manufactured using materials including a metalor combination of metals/alloy, a polymer, a plastic, glass, othermaterials, and any combination thereof. Furthermore, as shown in FIG. 9,body 902 has a plurality of openings or holes 906 formed therethrough.Holes 906 are open at both the top and bottom planar surfaces of body902. Although holes 906 are shown in FIG. 9 as being substantially roundor elliptical, they can have other shapes, including square orrectangular, or other shape.

[0091] FIGS. 10A-E show example schematic views of die plate 900,according to an example embodiment. For example, FIG. 10A shows a dieplate 900, and shows the outline of a wafer 400 superimposed on top ofdie plate 900. FIG. 10B also shows a die plate portion 1010 showing aclose-up view of a surface of die plate 900. As shown for portion 1010,die plate 900 has a plurality of holes 906, and in this particularembodiment, includes a plurality of grid lines 1002. Grid lines 1002 canbe formed on either or both of the bottom and top surfaces of die plate900. Grid lines 1002 can be used to indicate areas for placement of dies104 on die plate 900 and/or can be used as guidelines for sawing orotherwise separating dies 104 on die plate 1002. For example, grid lines1002 can be grooves in the surface of die plate 900 for an end of a sawblade to pass through. FIG. 10C also shows a plan view of a die plateportion 1020.

[0092]FIG. 11 shows a perspective view of a die plate portion 1100,according to an embodiment of the present invention. As shown in FIG.11, die plate portion 1100 includes holes 906, and grid lines 1002,which are shown as grooves in the surface of die plate 900.

[0093]FIG. 12 shows example steps related to a flowchart 1200 fortransferring dies from a support structure to die plate 900, accordingto embodiments of the present invention. Further operational andstructural embodiments of the present invention will be apparent topersons skilled in the relevant arts based on the following discussion.

[0094]FIGS. 13-15 relate to the steps of flowchart 1200 of FIG. 12. FIG.13 shows a plurality of dies 104 attached in a pads-down fashion to abottom surface of a support structure 404. FIG. 13 also shows across-sectional view of die plate 900. As shown in FIG. 13, an adhesivematerial layer 1302 has been formed on the top surface of die plate 900.Note that additionally or alternatively, an adhesive material can beapplied to the bottom surfaces of dies 104. Adhesive material layer 1302may be any type of adhesive material, including an epoxy, an adhesivetape, or any other adhesive material.

[0095]FIG. 14 shows an implementation of step 1202 of flowchart 1200shown in FIG. 12. As shown in FIG. 14, support structure 404 and dieplate 900 are positioned closely adjacent to each other, such that eachdie 104 attached to support structure 404 adheres to the top surface ofdie plate 900 due to adhesive material layer 1302.

[0096]FIG. 15 shows an example implementation of step 1204 of flowchart1200 shown in FIG. 12. As shown in FIG. 15, each die 104 is releasedfrom support surface 404, and therefore remains attached to die plate900. In an embodiment, for example, the adhesive force of adhesivematerial layer 1302 is stronger than the adhesive force of the bottomsurface of support structure 404. Thus, when support structure 404 ismoved away from die plate 900, dies 104 remain attached to die plate900. Thus, support structure may be peeled from die plate 900 totransfer dies 104.

[0097] Note that although a vacuum source is not shown or used in FIGS.13-15, in an alternative embodiment, a vacuum source can be used in thecurrent embodiment to aid in transferring dies 104 to die plate 900.

[0098] In further embodiments, dies 104 of a wafer 400 can be directlytransferred to die plate 900. FIG. 16 shows example steps related to aflowchart 1600 for transferring dies from a wafer to die plate 900,according to embodiments of the present invention. Further operationaland structural embodiments of the present invention will be apparent topersons skilled in the relevant arts based on the following discussion.

[0099]FIGS. 17-19 relate to the steps of flowchart 1600 shown in FIG.16. For example, FIG. 17 shows an example wafer having a plurality ofdies included therein, being positioned adjacent to a die plate 900.Note that in an embodiment, wafer 400 has been thinned so that it has athickness of approximately the thickness of a die. Furthermore, as shownin FIG. 17, an adhesive material layer 1302 has been applied to the topsurface of die plate 900. Note that additionally, or alternatively, anadhesive material may be applied to the bottom surface of wafer 400.

[0100]FIG. 18 shows an example implementation of step 1602 of flowchart1600 shown in FIG. 16. As shown in FIG. 18, wafer 400 and die plate 900are positioned closely adjacent to each other such that wafer 400adheres to the first surface of die plate 900. Note that die plate 900and wafer 400 are positioned such that each die 104 of wafer 400 coversa corresponding hole 906 through die plate 900 at the first or topsurface of die plate 900.

[0101]FIG. 19 shows an example implementation of step 1604 of flowchart1600 shown in FIG. 16. As shown in FIG. 19, each of dies 104 arescribed/separated from wafer 400 so that they remain attached to the topsurface of die plate 900. For example, as shown in FIGS. 18 and 19, asaw mechanism 1802 can be used to separate the dies 104 of wafer 400.The blade of saw mechanism 1802 may track the grooves or lines of grid1002 which can be optionally formed in the top surface of die plate 900.Saw mechanism 1802 can be a saw blade or other cutting device, can be alaser, or any other sawing or cutting device suitable for separatingdies from a wafer 400.

[0102] 2.1.1.1 Die Transfer onto a Die Plate from Partially Cut AdhesiveSurface

[0103]FIGS. 20-26 show various views of a transfer of dies to a dieplate, and subsequently to one or more substrates, according toembodiments of the present invention. FIG. 20 shows a wafer 400 attachedin a pads-up fashion to a surface of a support structure 404. Forexample, wafer 400 and support structure 400 may be held in aconventional wafer frame or other holding mechanism. As shown in FIG.20, a first die 104 is being separated from wafer 400. For example, asshown in FIG. 20, a saw mechanism 1802 (or other suitable device orprocess) can be used to scribe/separate die 104 of wafer 400.Furthermore, saw mechanism 1802 penetrates and cuts/separates a groovedepth 2002 of the total thickness 2004 of support structure 404 whenseparating first die 104 a from wafer 400, to form grooves 2006. Groovedepth 2002 can be any portion of the thickness 2004 of support structure404, as required by the particular application. As shown in FIG. 20,groove depth 2002 can be greater than 50% of thickness 2004, includingapproximately 90% of thickness 2004.

[0104] Note that although FIG. 20 shows dies 104 being separated whengrooves 2006 are formed, in another embodiment, dies 104 may alreadyhave been separated before grooves 2006 are formed. Thus, in such anembodiment, grooves 2006 may be formed in a subsequent processing stepto the actual scribing of wafer 400. Thus, the present application isapplicable to using scribed and un-scribed wafers.

[0105]FIG. 21 shows wafer 400 having a plurality of dies 104 a-dseparated, with grooves 2006 a-e formed in support structure 404 aroundeach of the plurality of dies 104. Furthermore, FIG. 21 shows wafer 400being positioned adjacent to a die plate 900 in preparation for transferof dies 104 to die plate 900. Note that because grooves 2006 penetratesupport structure 404 around each die 104, potentially weakening supportstructure 404, support structure 404 may sag when being positionedadjacent to die plate 900. Such sagging of support structure 404 maycreate difficulties in precisely aligning dies 104 over correspondingholes 906 through die plate 900. Thus, if groove depth 2002 is greatenough to cause significant sagging of support structure 404, a vacuumand/or positive pressure may be used to reduce or eliminate the sagging.For example, FIG. 22 shows a pressure source 2202 used to provide apositive pressure. For example pressure source 2202 provides a gaspressure 2204 directed through holes 906 of die plate 900 to reduce sagin support structure 404 when support structure 404 and die plate 900are being moved into contact. Alternatively or additionally, a vacuumsource may be applied to support structure 404 (e.g., from above supportstructure 404 in FIG. 22) to provide a vacuum/suction to reduce sag insupport structure 404.

[0106]FIG. 23 shows support structure 404 and die plate 900 positionedclosely adjacent to each other such that support structure 404 adheresto the first surface of die plate 900. Note that die plate 900 and wafer400 are positioned such that each of dies 104 a-d covers a correspondinghole 906 a-d through die plate 900 at the first or top surface of dieplate 900.

[0107]FIG. 24 shows a close up view of a die 104 a of FIG. 23, where dieplate 900 attaching support structure 404 and dies 104 has beeninverted. As shown in FIG. 24, a pin 2402 is inserted in hole 906 a tobe used to push/punch die 104 a from die plate 900. FIG. 25 shows pin2402 moving through hole 906 a of die plate 900 to contact supportstructure 404 opposite of die 104 a, to push die 104 a in contact with asubstrate 2502. Pin 2402 separates die 104 a from support structure 404by tearing/ripping support structure 404 around the perimeter of die 104a, such as at perimeter portions 2504 a and 2504 b in FIG. 24 (anadhesiveness of substrate 2502 may also contribute to thistearing/ripping of support structure 404).

[0108] Note that pin 2402 may be coupled to a pin plate having aplurality of pins 2402 that push/punch a plurality of dies 104 from dieplate 900 in parallel onto the same or multiple substrates. For example,in a multiple substrate embodiment, the substrates may be separate, orjoined together in a web of substrates. For further information onexample pin plates, refer to co-pending U.S. Application Serial No.______, titled “Method, System, And Apparatus For Transfer Of Dies UsingA Pin Plate,” having the same filing date as the present application,which is incorporated by reference in its entirety herein.

[0109]FIG. 26 shows die 104 a on substrate 2502, having been separatedfrom support structure 404 by pin 2402. As shown in FIG. 26 portion 2602of support structure 404 remains attached to die 104 a. Portion 2602 ofsupport structure 404 helps to protect die 104 a from damage due to pin2402 during transfer of die 104 to substrate 2502. Portion 2602 attachedto die 104 a can subsequently be removed from die 104 a if desired, orcan remain on die 104 a when the respective tag or other deviceincluding substrate 2502 is completed. For example, portion 2602 canremain on die 104 a to provide environmental protection for die 104 a.

[0110]FIG. 27 shows a flowchart providing steps for transferring dies,according to embodiments of the present invention. For example, FIG. 27relates to the transfer of dies shown in FIGS. 20-26. Further structuralembodiments of the present invention will be apparent to persons skilledin the relevant art(s) based on the following discussion. These stepsare described in detail below.

[0111] In step 2702, grooves are formed in a first surface of a supportstructure that attaches a plurality of dies. For example, the groovesare grooves 2006 formed in support structure 404, as shown in FIGS.20-25. Note that the dies attached to the support structure may beseparate on the support structure, or included in a wafer, prior toformation of the grooves.

[0112] In step 2704, a second surface of the support structure and a dieplate are moved into contact with each other so that the supportstructure attaches to the die plate. For example, as shown in FIG. 23,the bottom surface of support structure 404 is moved into contact withdie plate 900, to become attached to die plate 900. Note that in anembodiment, as described above, a positive pressure can be applied tothe support structure to reduce sag in the support structure.

[0113] In an embodiment, flowchart 2700 includes step 2706. In step2706, at least one hole through the die plate is punched through totransfer a corresponding die from the die plate to a destinationsurface. For example, as shown in FIGS. 24 and 25, pin 2402 passesthrough hole 906 a to transfer die 104 a from die plate 900 to substrate2502. Note that in an embodiment, the support structure around thecorresponding die is torn to release the die from the support structure.In an embodiment, a portion of the support structure remains attached tothe die.

[0114] 2.1.2 Example Die Plate Embodiments

[0115] As described above, FIGS. 10A-E show example schematic views ofdie plate 900, according to an illustrative embodiment of the presentinvention. As described above, a die plate can be made from a variety ofmaterials. In an embodiment, a die plate is made from the same materialas a corresponding pin plate is made, or from a material having the samecoefficient of thermal expansion (CTE) as a corresponding pin plate, sothat the die plate and pin plate will expand and contract uniformly dueto changes in temperature. For example, a die plate and correspondingpin plate can be from aluminum. In another example, one of the die plateand corresponding pin plate are made from Kapton, while the other ismade from aluminum, because Kapton and aluminum have very similar CTEvalues. Alternatively, both can be made from Kapton.

[0116] As described above, FIG. 10A shows a die plate 900, and shows theoutline of a wafer 400 superimposed on top of die plate 900. Die plate900 can have any shape and size, as required by a particularapplication. For example, die plate 900 shown in FIG. 10A can have awidth and length of approximately 254 mm. Wafer 400 can have a diameterof approximately 203 mm, for example. Die plate 900 can have holes 906spaced according to any distances, as required by a particularapplication. For example, in one embodiment, die plate 900 can have ahole pattern of 103×205 holes spaced apart 2 mm horizontally and 1 mmvertically for a total number of 21,115 holes (e.g., for rectangulardie). Such a pattern can cover a 204 mm×204 mm pattern (from hole centerto hole center).

[0117]FIG. 10C shows a plan view of a die plate portion 1020. Holes 906can have any diameter, as required by a particular application.Typically, holes 906 have a diameter less than or equal to a minimum ofthe width and length of a corresponding die. For example, hole 906 shownin FIG. 10C can have a diameter of approximately 0.584 mm to accommodatea die having a width of approximately 0.949 mm and a length ofapproximately 1.949 mm. FIGS. 10D and 10E show cross-sectional views ofportions of die plate 900. Grooves 1002 can have any widths and depths,as required by a particular application. For example, grooves 1002 shownin FIGS. 10D and 10E can have widths of approximately 0.051 mm anddepths of approximately 0.051 mm.

[0118] It is noted that any of the sizes/dimensions, spacings, numbersof holes, etc., described above are provided for illustrative purposes.It will be apparent to persons skilled in the relevant art(s) that theseparameters can be modified as needed for a particular application. Forexample, these parameters can be modified for particular wafer sizes,die sizes, number of dies to be transferred in parallel, etc.

CONCLUSION

[0119] While various embodiments of the present invention have beendescribed above, it should be understood that they have been presentedby way of example, and not limitation. It will be apparent to personsskilled in the relevant arts that various changes in form and detail canbe made therein without departing from the spirit and scope of theinvention. Thus the present invention should not be limited by any ofthe above-described exemplary embodiments, but should be defined only inaccordance with the following claims and their equivalents.

What is claimed is:
 1. A method for transferring a plurality ofintegrated circuit dies that are attached to a support structure to adie plate, comprising: (a) positioning the support structure and dieplate to be closely adjacent to each other such that each die of aplurality of dies attached to the support structure adheres to a firstsurface of the die plate due to an adhesive material; and (b) releasingeach die of the plurality of dies from the support structure so thateach die remains attached to the die plate.
 2. The method of claim 1,wherein step (b) comprises: moving apart the support structure and dieplate.
 3. The method of claim 2, wherein said moving step comprises:moving apart the support structure and die plate so that each dieremains attached to the die plate due to the adhesive materialovercoming an adhesiveness of the support structure.
 4. The method ofclaim 2, wherein step (a) comprises: positioning the support structureand die plate to be closely adjacent to each other such that each die ofthe plurality of dies covers a corresponding hole through the die plate,wherein each hole is open at the first surface and second surface of thedie plate.
 5. The method of claim 4, further comprising: (c) applying asuction at a second surface of the die plate that further adheres eachdie to the die plate due to the corresponding hole.
 6. The method ofclaim 1, further comprising: (c) applying the adhesive material to thefirst surface of the die plate.
 7. The method of claim 1, wherein afirst surface of each die is attached to the support structure, furthercomprising: (c) applying the adhesive material to a second surface ofeach die of the plurality of dies.
 8. The method of claim 2, wherein thesupport structure is a tape structure, wherein said moving stepcomprises: peeling the support structure from the die plate.
 9. A methodfor transferring a plurality of integrated circuit dies from a wafer toa die plate, comprising: (a) positioning the wafer and die plate to beclosely adjacent to each other such that the wafer adheres to a firstsurface of the die plate due to an adhesive material, wherein the dieplate includes a plurality of holes, wherein each hole is open at thefirst surface and a second surface of the die plate, wherein each die ofa plurality of dies of the wafer covers a corresponding hole through thedie plate; and (b) separating each die of the plurality of dies from thewafer so that each die remains on the die plate.
 10. The method of claim9, wherein step (b) comprises: sawing each die of the plurality of diesfrom the wafer.
 11. The method of claim 10, wherein said sawing stepcomprising: sawing along grooves in the first surface of the die platethat are positioned at boundaries between adjacent dies of the pluralityof dies of the wafer.
 12. The method of claim 9, further comprising: (c)applying a suction at a second surface of the die plate that furtheradheres the wafer to the die plate due to the plurality of holes. 13.The method of claim 9, further comprising: (c) applying the adhesivematerial to the first surface of the die plate.
 14. The method of claim9, further comprising: (c) applying the adhesive material to a surfaceof the wafer.
 15. The method of claim 9 wherein step (b) comprises:using a laser to separate each die of the plurality of dies from thewafer.
 16. A method for transferring a plurality of integrated circuitdies, comprising: (a) forming grooves in a first surface of a supportstructure that attaches a plurality of dies, wherein the grooves areformed in the surface of the support structure between the dies; and (b)moving a second surface of the support structure and a die plate intocontact with each other so that the support structure attaches to thedie plate, and so that a portion of the support structure attaching eachdie of the plurality of dies covers a corresponding hole through the dieplate.
 17. The method of claim 16, wherein the plurality of dies areincluded in a wafer, wherein step (a) comprises: cutting through thewafer to separate the dies from the wafer and to form the grooves in thesurface of the support structure.
 18. The method of claim 16, whereinthe plurality of dies are separate on the support structure, whereinstep (a) comprises: forming the grooves in the surface of the supportstructure through channels between the dies.
 19. The method of claim 16,further comprising: (c) applying a positive pressure to the supportstructure to reduce sag in the support structure.
 20. The method ofclaim 16, further comprising: (c) punching through at least one holethrough the die plate to transfer a corresponding die from the die plateto a destination surface.
 21. The method of claim 20, wherein step (c)comprises: tearing the support structure around the corresponding die torelease the die from the support structure, wherein a portion of thesupport structure remains attached to the die.
 22. A die plate,comprising: a planar body, wherein said body comprises a plurality ofholes therethrough.
 23. The die plate of claim 22, further comprising: adie attachment position corresponding to each hole of said plurality ofholes.
 24. The die plate of claim 23, wherein each hole has a diameterless than or equal to (≦) a width of an integrated circuit die.
 25. Thedie plate of claim 22, wherein said plurality of holes are arranged inan array defined by a plurality of rows and a plurality of columns ofholes.
 26. The die plate of claim 25, comprising a plurality of groovesin a first surface of said die plate.
 27. The die plate of claim 26,wherein said plurality of grooves are positioned between said rows ofholes and between said columns of holes in said first surface.
 28. Thedie plate of claim 26, wherein said plurality of grooves are used duringscribing of a wafer attached to said die plate.
 29. The die plate ofclaim 22, further comprising an adhesive material covering at least aportion of a first surface of said planar body.
 30. A system fortransferring dies, comprising: a die plate, comprising: a planar body,wherein said body comprises a plurality of holes therethrough.
 31. Thesystem of claim 30, further comprising: a frame that holds a supportstructure that attaches a plurality of dies.
 32. The system of claim 31,further comprising: a wafer separator for separating the plurality ofdies from a wafer on the support structure.
 33. The system of claim 32,wherein the wafer separator includes a wafer saw.
 34. The system ofclaim 32, wherein the wafer separator includes a laser.
 35. The systemof claim 30, further comprising: a vacuum source.
 36. The system ofclaim 30, further comprising: a positive pressure source.
 37. The systemof claim 30, further comprising: a pin plate that mounts at least onepin, wherein said at least one pin is used to pass through at least onecorresponding hole of said plurality of holes to punch at least onecorresponding die from said die plate.